Clueless New Puppy Owner Looking for Help

I have an 8-month old puppy who weighs about 16.5 lbs. We have had him for 6 months, and this is my first puppy…so please be patient with me 🙂

About a month and a half ago, Milo had diarrhea. After 2 days, I took him to the vet. The vet gave him Flagyl, and told me to feed him boiled chicken and steamed rice, perhaps with a little canned pumpkin mixed in. This firmed up the stool so that it was “soft” rather than true diarrhea. The fecal test came back negative.

We continued the diet as suggested. Then it seemed like there was a day and a half where he would strain/squat, but nothing came out. We went back to the vet, and this time, they gave us an antibiotic, and also a probiotic (both a paste and capsules). We finished those, and the stools seem to firm up a bit…but as soon as we add even a little bit of kibble in (originally Diamond Naturals Chicken & Rice, then Stella & Chewy Raw Coated, then and now TOTW that doesn’t have chicken in it)…it goes back to soft serve ice cream consistency.

Milo is a happy camper. He does not seem sick at all. He still only poops 2-3 times per day, and never has accidents.

I am worried that so many weeks on chicken and rice is not good for him. The vet has now suggested I bring him in for an expensive malabsorption blood panel.

Could it be a chicken allergy?
Could it be the flea medication he took a couple of days before this all started?

I hope you will continue to work closely with your vet. A lot of misinformation on the internet
There are no veterinarians affiliated with DFA and even if there were, they have not examined your dog so they would not be able to give you specific advice.